hawkins



no Mode1 F. H. HAWKINS.

. PULVERIZED FUEL BURNER.

No. 510,788. Patented Dec. 12, 18 93.

UNITED STATES PATE T. OFFICE.

FREDERICK H. HAWKINS, on NEW YORK, N. Y.

PU LVERlZED-FU El. BURN ER.

SPECIFICATION forming part of Letters Patent No. 510,788, dated December12, 1893.

Application filed March 27, 1893- Serial No. 467,835. (No model.)

To all whom it may concern.-

Be it known that I, FREDERICK H. HAWKINS, a subject of the Queen ofGreat Britain, residing at New York city, in the countyof New York andState of New York, have invented certain new and useful Improvements inPulverized-Fuel Burners; and I do declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to an improved apparatus for, and method ofburning pulverized coal mingled with atmospheric air, to be used as afuel in furnaces for steam boilers, and other places where a very highheat is required.

The prime object of the invention is to reduce the cost of operating afurnace or engine by employing a cheap coal which when pulverized andmingled with air, and fed to suitable burners in a fire chamber, willgive a very high heat.

A further object of the invention is to subject such powdered orpulverized coal and the mingled air to the action of heat in a chamberor retort before it enters the burners or fire chamber so that as suchmass reaches the point for ignition it will be in the form of a highlyattenuated gas, or at least in a partly gaseous state, thereby makingthe combustion very rapid and the heat very intense.

Other objects and advantages will appear from the following descriptionand claims, when taken inconnection with the annexed drawings, in whichI have illustrated my apparatus in connection with a horizontal steamboiler, although it is obvious that other forms of boiler may beemployed without departing from the spirit of my invention.

In the drawings: Figure 1, is a plan view of my improved apparatus withthe boiler removed and the furnace walls in section, and alsoillustrating one type of a pulverizer and blower. Fig. 2, is a verticallongitudinal sectional view taken in the plane indicated by the dottedline w, x, on Fig. 1. Fig. 3, is a vertical transverse sectional viewtaken in the plane indicated by the dotted line y, y, on Fig. 1. Fig. 4,is a similar sectional view taken in the plane indicated by the dottedline 2, z, of Fig. 1, with the burners in position, and Fig. 5, is asectional detail view of one of the transverse feed pipes, and one ofthe burners. together with the grate bars,

illustrating the refractory material upon the latter.

Referring by letter to said drawings: A, indicates a furnace which maybe of any ordinary or approved construction, and B, indicates the bridgewall thereof.

0, indicates a boiler which is here shown as a horizontal boileralthough it is obvious that other forms may be employed.

D, indicates the grate bars which may be also of the constructionusually employed.

E, indicates a pulverizer, and F, a blower, connected with thepulverizer by means of a pipe or conduit a.

G, indicates a retort or chamber of a suitable capacity, and arrangedjust in rear of the bridge wall ofthe furnace. Leading from one end ofthis retort or chamber is a longitudinal pipe H, which connects at itsopposite end with the blower as shown. This pipe H, is preferablyarranged at an altitude to come. in contact with the heat in thecombustion chamber or fire box, and passes through the front wall ofsaid chamber as shown and along one of the inner side walls of thefurnace. This pipe is designed to take the powdered or pulverized coalfrom the blower where it is mingled with air, and force the same intothe chamber or retort G, where said pulverized coal and mingled air willexpand and by the action of heat become highly attenuated and at leastpartly converted into a gaseous state. Leading from the opposite end ofthis retort or expansion chamber and at a less altitude than the pipe H,is a pipe I, which is designed to receive the fuel in thishighlyattenuated condition and conduct it to feed pipes or tubes K. These feedpipes or tubes K, are arranged transversely within the fire chamber at asuitable distance below the grate bars and are provided with a suitablenumber of apertures 17, at intervals along their upper sides as shown sothat the pulverized or ground fuel and mingled air, as it is taken fromthe retort or expansion chamber, will be discharged into the transversefeed pipes or tubes, and from there through the apertures b.

Arranged over each aperture 1), in the feed pipes or tubes is what isknown as a Bunsen burner c. In some cases other forms of burners mightbe employed but I prefer the use of the Bunsen burner as it will aidmaterially in drawing up any air which might be in the ash box or belowthe grate. These burners comprise a base section d, which is of atruncated cone shape, and an upper section 6, placed with its large endupon the top of the base section, with a space between the adjacent endsto admit the passage of air upwardly. These burners are arranged belowand between the grate bars with their outlets slightly above the gratebars, as shown. It is designed to place the refractory material as shownby L, in Fig, 5, upon the grate bars. I have not given any detaildescription of the construction of blower or pulverizer, as they form nopart of my invention, and while I have shown these devices as providedwith pulleys to receive drive belts, yet they may be operated by anysuitable motive power.

In operation, after the refractory material has been placed upon thegrate bars, and the pulverized coal has been mingled with air, it isforcibly carried by means of the pipe II, into the retort or expansionchamber G, where it will quickly expand as it becomes heated, and fromthence it is carried out at the opposite end of said retort by means ofthe longitudinal pipe I, where it is distributed through the feed tubesK, and thence fed to the burners c, where ignition takes place, and therefractory material becoming incandescent, a Very high and intense heatwill be had.

Having described my invention, what I claim is- 1. The method of burningpulverized coal and mingled air, consisting first in mingling thepulverized coal with air, then heating and expanding such commingledmass, in a retort constituting an expansion chamber and finally carryingoff the heated and attenuated mass to burners and igniting the same,substantially as described.

2. The combination with a furnace or fire chamber; of a retortconstituting an expansion chamber, arranged so as to be heated by thefurnace fire, means for charging the retort and expansion chamber withcommingled air and comminuted coal, and a conduit or conveyer connectingthe retort and expansion chamber with the furnace chamber and adapted toreceive the fuel from said retort and expansion chamber and dischargethe same into the furnace chamber, substantially as described.

3. The combination with a furnace or fire chamber; of a retort orexpansion chamber arranged therein, a pipe leading from one end of saidexpansion chamber, branch pipes leading laterally therefrom beneath thegrate bars and provided with apertures on their upper sides, burnersarranged over the apertures, and a pipe leading from the opposite end ofthe retort or expansion chamber and adapted to receive pulverized coalmingled with air, and feed the same, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

FREDERICK H. HAWKINS.

Witnesses:

L. A. HAYWARD, E. LAMKIN.

